//-----------------------------------------------------------------------------
// Copyright 2015 Thiago Alves
//
// Based on the LDmicro software by Jonathan Westhues
// This file is part of the OpenPLC Software Stack.
//
// OpenPLC is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// OpenPLC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with OpenPLC.  If not, see <http://www.gnu.org/licenses/>.
//------
//
// This file is the hardware layer for the OpenPLC. If you change the platform
// where it is running, you may only need to change this file. All the I/O
// related stuff is here. Basically it provides functions to read and write
// to the OpenPLC internal buffers in order to update I/O state.
// Thiago Alves, Dec 2015
//-----------------------------------------------------------------------------

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <wiringPi.h>
#include <wiringSerial.h>
#include <pthread.h>

#include "ladder.h"

#if !defined(ARRAY_SIZE)
    #define ARRAY_SIZE(x) (sizeof((x)) / sizeof((x)[0]))
#endif

int serialFd; //serial file descriptor

//-----------------------------------------------------------------------------
// This function is called by the main OpenPLC routine when it is initializing.
// Hardware initialization procedures should be here.
//-----------------------------------------------------------------------------
void initializeHardware()
{
    wiringPiSetup();
    //piHiPri(99);

    serialFd = serialOpen("/dev/ttyUSB0", 9600);
    if (serialFd < 0)
    {
        printf("Error trying to open serial port\n");
        exit(1);
    }
}

//-----------------------------------------------------------------------------
// This function is called by the main OpenPLC routine when it is finalizing.
// Resource clearing procedures should be here.
//-----------------------------------------------------------------------------
void finalizeHardware()
{
}

void sendOutput(unsigned char *sendBytes, unsigned char *recvBytes)
{
    long serialTimer;

    /*
    //==================================================================
    //READING ANALOG VALUE EX
    //==================================================================
    serialPutchar(serialFd, 0xC5);
    serialPutchar(serialFd, sendBytes[1]);

    serialTimer = millis();
    while ((serialDataAvail(serialFd) < 3) && (millis() - serialTimer < 100)) {} //wait until timeout

    if (serialDataAvail(serialFd) == 3) //received 3 bytes correctly
    {
        recvBytes[0] = serialGetchar(serialFd); //this one will be discarded
        recvBytes[2] = serialGetchar(serialFd); //EX high
        recvBytes[3] = serialGetchar(serialFd); //EX low
    }
    else
    {
        //corrupted data - discard
        printf("corrupted1\n");
        while (serialDataAvail(serialFd) > 0)
        {
            unsigned char discard = serialGetchar(serialFd);
        }
    }

    //==================================================================
    //READING ANALOG VALUE EY
    //==================================================================
    serialPutchar(serialFd, 0xC9);
    serialPutchar(serialFd, sendBytes[1]);

    serialTimer = millis();
    while ((serialDataAvail(serialFd) < 3) && (millis() - serialTimer < 100)) {} //wait until timeout

    if (serialDataAvail(serialFd) == 3) //received 3 bytes correctly
    {
        recvBytes[0] = serialGetchar(serialFd); //this one will be discarded
        recvBytes[4] = serialGetchar(serialFd); //EY high
        recvBytes[5] = serialGetchar(serialFd); //EY low
    }
    else
    {
        //corrupted data - discard
        printf("corrupted2\n");
        while (serialDataAvail(serialFd) > 0)
        {
            unsigned char discard = serialGetchar(serialFd);
        }
    }
    */

    //==================================================================
    //READING AND WRITING DIGITAL IO
    //==================================================================
    serialPutchar(serialFd, sendBytes[0]);
    serialPutchar(serialFd, sendBytes[1]);
    serialPutchar(serialFd, sendBytes[2]);

    serialTimer = millis();
    while ((serialDataAvail(serialFd) < 2) && (millis() - serialTimer < 100)) {} //wait until timeout

    if (serialDataAvail(serialFd) == 2) //received 2 bytes correctly
    {
        recvBytes[0] = serialGetchar(serialFd);
        recvBytes[1] = serialGetchar(serialFd);
    }

    else
    {
        //corrupted data - discard
        printf("corrupted3\n");
        while (serialDataAvail(serialFd) > 0)
        {
            unsigned char discard = serialGetchar(serialFd);
        }
    }
}

//-----------------------------------------------------------------------------
// This function is called by the OpenPLC in a loop. Here the internal buffers
// must be updated to reflect the actual Input state. The mutex bufferLock
// must be used to protect access to the buffers on a threaded environment.
//-----------------------------------------------------------------------------
void updateBuffersIn()
{
    unsigned char sendBytes[3], recvBytes[6], i;
    sendBytes[0] = 0xC2; //read and write IO for both modules
    sendBytes[1] = 0; //make sure output is off
    sendBytes[2] = 0; //make sure output is off

    pthread_mutex_lock(&bufferLock);
    for (i=0; i<8; i++)
    {
        if (bool_output[0][i] != NULL) sendBytes[1] = sendBytes[1] | (*bool_output[0][i] << i); //write each bit
    }
    for (i=8; i<16; i++)
    {
        if (bool_output[1][i%8] != NULL) sendBytes[2] = sendBytes[2] | (*bool_output[1][i%8] << (i-8)); //write each bit
    }
    pthread_mutex_unlock(&bufferLock);

    sendOutput(sendBytes, recvBytes);

    pthread_mutex_lock(&bufferLock);
    //if (int_input[0] != NULL) *int_input[0] = (int)(recvBytes[2] << 8) | (int)recvBytes[3]; //EX
    //if (int_input[1] != NULL) *int_input[1] = (int)(recvBytes[4] << 8) | (int)recvBytes[5]; //EY

    for (i=0; i<8; i++)
    {
        if (bool_input[0][i] != NULL) *bool_input[0][i] = (recvBytes[0] >> i) & 0x01;
        //printf("%d\t", DiscreteInputBuffer0[i]);
    }
    for (i=8; i<16; i++)
    {
        if (bool_input[1][i%8] != NULL) *bool_input[1][i%8] = (recvBytes[1] >> (i-8)) & 0x01;
        //printf("%d\t", DiscreteInputBuffer0[i]);
    }
    //printf("\n");
    pthread_mutex_unlock(&bufferLock);
}

//-----------------------------------------------------------------------------
// This function is called by the OpenPLC in a loop. Here the internal buffers
// must be updated to reflect the actual Output state. The mutex buffer_lock
// must be used to protect access to the buffers on a threaded environment.
//-----------------------------------------------------------------------------
void updateBuffersOut()
{
    unsigned char sendBytes[3], recvBytes[6], i;
    sendBytes[0] = 0xC2; //read and write IO for both modules
    sendBytes[1] = 0; //make sure output is off
    sendBytes[2] = 0; //make sure output is off

    pthread_mutex_lock(&bufferLock);
    for (i=0; i<8; i++)
    {
        if (bool_output[0][i] != NULL) sendBytes[1] = sendBytes[1] | (*bool_output[0][i] << i); //write each bit
    }
    for (i=8; i<16; i++)
    {
        if (bool_output[1][i%8] != NULL) sendBytes[2] = sendBytes[2] | (*bool_output[1][i%8] << (i-8)); //write each bit
    }
    pthread_mutex_unlock(&bufferLock);

    sendOutput(sendBytes, recvBytes);

    pthread_mutex_lock(&bufferLock);
    //if (int_input[0] != NULL) *int_input[0] = (int)(recvBytes[2] << 8) | (int)recvBytes[3]; //EX
    //if (int_input[1] != NULL) *int_input[1] = (int)(recvBytes[4] << 8) | (int)recvBytes[5]; //EY

    for (i=0; i<8; i++)
    {
        if (bool_input[0][i] != NULL) *bool_input[0][i] = (recvBytes[0] >> i) & 0x01;
        //printf("%d\t", DiscreteInputBuffer0[i]);
    }
    for (i=8; i<16; i++)
    {
        if (bool_input[1][i%8] != NULL) *bool_input[1][i%8] = (recvBytes[1] >> (i-8)) & 0x01;
        //printf("%d\t", DiscreteInputBuffer0[i]);
    }
    //printf("\n");
    pthread_mutex_unlock(&bufferLock);
}

